Pipe joint for pump

ABSTRACT

A pipe joint for a pump including a pump casing having a pipe connecting flange, comprising a flange body produced from a steel plate such that the inner peripheral portion thereof that defines a water passage is extended toward the casing body and secured by welding to an outlet/inlet opening in the casing body directly or through a cylindrical member, the flange body having a plurality of bolt holes provided in a flange face thereof, and a retainer plate being installed in such a manner as to abut against the reverse side of the flange face, the retainer plate having an annular rib with a square outer shape and a U-shaped cross section which projects toward the casing body, the annular rib being provided in the bottom of the U-shaped cross section with a plurality of bolt holes respectively corresponding to the bolt holes, the retainer plate further having a raised face formed integral with the annular rib at the inner side thereof or at each of the outer and inner sides thereof such that the raised face abuts against the reverse side of the flange face.

TECHNICAL FIELD

The present invention relates to a structure of a pipe joint at each oreither one of the suction and discharge opening sides of a pump producedfrom steel plate, for example, stainless steel plate.

BACKGROUND ART

A typical conventional pipe joint of a pump produced from steel platehas a structure such as that shown in FIG. 1. At the discharge side, apipe connecting flange 2 having a discharge opening 2a is welded to adischarge opening portion provided in the peripheral surface portion 1aof a casing body 1, and a thick-walled iron plate 3 is welded to thereverse side of the flange face of the pipe connecting flange 2.

At the suction side, on the other hand, a suction flange 4 having asuction opening 4a is welded to a suction opening portion provided inthe suction-side side surface portion 1b of the casing body 1, and athick-walled steel plate 5 having a bolt hole 5a is welded to thereverse side of the suction flange 4. It should be noted that in thefigure, the reference numeral 6 denotes a suction partition plate, 7 avolute inner wall having bores 7a in the periphery thereof, 8 a casingcover, and 9 an impeller.

In the prior art shown in FIG. 2, a box shaped support member 15 isprovided at the suction joint of a pump casing 11 formed from a thinplate (steel plate) in such a manner that the box shaped support member15 surrounds a short suction pipe 12, the box shaped support member 15comprising a suction-side casing wall 11a, a connecting flange 13 and asupport member 14 which extends between the connecting flange 13 and thepump casing 11. In the figure, the reference numeral 16 denotes a casingend wall (see West Germany Patent Laid-Open Publication No. 3517828).

In the above-described prior art, the one (FIG. 1) in which athick-walled steel plate is welded to the reverse side of the flangeface of the pipe connecting flange has a disadvantageously high cost,although the flange face portion has a satisfactorily high strength. Inthe prior art (FIG. 2) in which the suction-side connecting flange 13 issupported by the support member 14 that is disposed outside the shortsuction pipe 12, since the whole of the connecting flange 13 having athick wall, needs to be formed using a corrosion-resistant material andfurther, since the intermediary water passage (short suction pipe) 12 isalso a separate member, the prior art necessitates the expenditure of agreat many of man-hours and the cost is high.

In view of the above-described circumstances, it is an object of thepresent invention to provide a pipe joint for a pump which has acorrosion-resistant flow path and high rigidity at the flange jointsurface and which is capable of preventing deformation by theapplication of an external force to the flange.

DISCLOSURE OF THE INVENTION

To attain the above-described object, the present invention provides thefollowing structure for a pump pipe joint.

The pipe joint for a pump according to the invention comprises a flangebody produced from a steel plate such that the inner peripheral portionthereof that defines a water passage is extended toward the casing bodyand secured by welding to an outlet/inlet opening in the casing bodydirectly or through a cylindrical member, the flange body having aplurality of bolt holes provided in a flange face thereof, and aretainer plate installed in such a manner as to abut against the reverseside of the flange face, the retainer plate having an annular rib with asquare outer shape and a U-shaped cross section which projects towardthe casing body, the annular rib being provided in the bottom of theU-shaped cross section with a plurality of bolt holes respectivelycorresponding to the bolt holes in the flanges face, the retainer platefurther having a raised face formed integral with the annular rib at theinner side thereof such that the raised face abuts against the reverseside of the flange face. The retainer plate may have another raised faceformed integral with the annular rib at the outer side thereof such thatthe secondraised face abuts against the reverse side of the flange face.

The pipe joint may further comprise a reinforcing flange installed insuch a manner as to abut against the bottom of the annular rib of theretainer plate. The reinforcing flange includes a cylindrical portionhaving a larger bore than that of the outlet/inlet opening in the casingbody, an extended portion formed by radially outwardly extending the endportion of the cylindrical portion on the side thereof which is closerto the flange, the extended portion being joined to an outer cylindricalportion of the flange body, the extended portion being provided withbolt holes respectively corresponding to the bolt holes in the flangeface and the retainer plate, and a casing-side end portion of thecylindrical portion which is formed in conformity with the configurationof the casing body and welded thereto.

In addition, an outwardly projecting rib may be provided on a part ofthe cylindrical portion of the reinforcing flange.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are sectional views of pumps having conventional pipejoints, respectively;

FIGS. 3(a) and 3(b) are plan and sectional views, respectively, of apipe joint according to one embodiment of the present invention;

FIG. 4 is a sectional view of a pipe joint according to anotherembodiment of the present invention;

FIG. 5(a) is a plan view of a reinforcing flange; and

FIG. 5(b) is a sectional view showing the reinforcing flange in aninstalled state.

FIG. 5(c) is similar to FIG. 5(b), but shows a different sectional view.

FIG. 6 is a sectional view of the flange body of the invention beingconnected directly to the pump casing body.

FIG. 7 is a sectional view of an embodiment of the invention with theflange body is connected to inlet opening of the casing body through acylindrical member.

BEST MODE FOR CARRYING OUT THE INVENTION

The mode for carrying out the present invention will be described belowwith reference to the drawings.

FIG. 3(a) is a plan view of a discharge-side pipe joint of a pumpaccording to one embodiment of the present invention, and FIG. 3(b) is asectional view taken along the line AOB of FIG. 3(a).

Referring to the figures, a flange body 21 is produced from athin-walled corrosion-resistant steel plate. The inner peripheralportion 21b of the flange face (the surface on which an opposing flangeabuts) 21a that defines a water passage extends inward from the flangeface 21a and is hermetically welded to an outlet opening 22a in thecasing through a substantially cylindrical discharge nozzle 25 tothereby maintain watertightness. At the outer periphery of the flangeface 21a, an outer cylindrical portion 21c is formed which extendstoward the casing body 22, thereby providing a reinforcing rib effectand improving the external appearance.

At the reverse side of the flange face 21a is provided a relativelythick-walled retainer plate 23 which extends from the outer side of theinner peripheral portion 21b of the flange body 21 to the outerperipheral portion which corresponds to the raised face (R.F. portion)of an ordinary flange, and the retainer plate 23 is rigidly secured tothe reverse side of the flange body 21. The retainer plate 23 has anannular rib 23R with a U-shaped cross section which projects toward thecasing body 22 at a portion adjacent to the raised face. The annular rib23R comprises a planar bottom portion (the bottom of the U-shaped crosssection) 23b which is provided with bolt holes 23a respectivelycorresponding to bolt holes 21d in the flange body 21, a cylindricalportion 23c which is provided at the radially inner side of the planarportion 23b so as to have a height substantially equal to that of theouter peripheral cylindrical portion 21c of the flange body 21, a squarebox-shaped portion 23d which is provided at the radially outer side ofthe planar portion 23b so as to have a height substantially equal tothat of the outer peripheral cylindrical portion 21c, and a raised face23e which projects radially inward from the upper end of the cylindricalportion 23c as far as a position near the inner peripheral portion 21bso as to abut against the reverse side of the flange face 21a. Theraised face 23e constitutes the R.F. portion.

Although in the foregoing embodiment the discharge nozzle pipe 25 is apart which is separate from the flange body 21, it should be noted thatthe inner peripheral portion of the flange body 21 may be extended asfar as the outlet opening 22a to form a discharge nozzle pipe portion asan integral part of the flange body 21.

FIG. 4 is a sectional view [similar to that taken along the line AOB ofFIG. 3(a)] of a pipe joint at the discharge side of a pump, which showsanother embodiment of the present invention.

In this embodiment, the retainer plate 23 comprises a raised face 23fwhich projects outward from the upper end of the box-shaped portion 23dto a position near the outer cylindrical portion 21c in addition to theraised face 23e that projects as far as a position near the innerperipheral portion 21b so as to abut against the reverse side of theflange face 21a. These raised faces 23e and 23f constitute incombination the R.F. portion.

Further, a reinforcing flange 24 is installed on the reverse side of theflange body 21 so as to abut against the planar portion 23b thatconstitutes the bottom of the retainer plate 23. The reinforcing plate24 has a cylindrical portion 24a which has a larger bore than that ofthe outlet opening 22a in the casing body 22. The cylindrical portion24a is extended toward the flange (upward as viewed in the figure) tothe same level as that of the lower end face of the retainer plate 23.The end portion of the extended cylindrical portion 24a is furtherextended radially outward and bent at the extremity thereof so as to bejoined to the inner side of the outer cylindrical portion 21c of theflange body 21. In this state, the extended portion 24b is in contactwith the lower surface of the annular rib of the retainer plate 23. Theextended portion 24b is provided with bolt holes 24c respectivelycorresponding to the bolt holes 21d and 23a. The end portion 24 d of thecylindrical portion 24a on the side thereof which is closer to thecasing (i.e., the lower end portion as viewed in the figure) is formedso as to be conformable to the configuration of the casing body 22 andwelded thereto.

FIG. 5(a) is a fragmentary plan view of the reinforcing flange 24. FIG.5(b) is a sectional view taken along the line COD of FIG. 5(a), and FIG.5(c) is a sectional view taken along the line EOD. As illustrated in thefigures, a part of the cylindrical portion 24a of the reinforcing flange24 projects outward to form an outwardly projecting rib 24e.

By virtue of the above-described arrangement, in the pipe joint shown inFIG. 3(b) the raised face 23e of the retainer plate 23 which is disposedso as to abut against the reverse side of the flange face 21a of theflange body 21 when bolted functions as a reinforcing member. In thepipe joint shown in FIG. 4, the raised faces 23e and 23f of the retainerplate 23 function as reinforcing members.

Since the retainer plate 23 has as an integral part thereof an annularrib 23R having a U-shaped cross section which comprises a planar portion23b provided with bolt holes 23a and a square box-shaped portion 23dformed at the outer side of the planar portion 23b, the edges of thebox-shaped portion 23d function as ribs which prevent deformation of aportion of the retainer plate 23 which extends between each pair ofadjacent bolts when the retainer plate 23 is bolted. Although torsionalforce also acts on the retainer plate 23 when bolted, the edges of thebox-shaped portion 23d also function so as to enhance the rigidity tothe torsion.

The reinforcing flange 24 that is installed on the reverse side of theflange body 21 functions so as to prevent deformation of the flange body21 caused by the application of an external force to the flange body 21.The rib 24e that is formed on the cylindrical portion 24a of thereinforcing flange 24 further enhances the strength of the reinforcingflange 24 and hence enhances its effectiveness in preventing deformationof the flange body 21.

It should be noted that in the foregoing embodiments the cylindricalportion 23c of the retainer plate 23 need not necessarily be a circularcylinder and that it may, as a matter of course, have any cylindricaltype configuration, for example, a polygonal cylinder-shapedconfiguration.

Although in the foregoing embodiments the pipe joint at the dischargeside of a pump has been explained, the above-described pipe jointstructure may be similarly applied to the suction side of a pump, as amatter of course.

As has been described above, it is possible according to the presentinvention to obtain the following advantageous effects.

The arrangement that a flange body is produced from a steel plate suchthat the inner peripheral portion thereof that defines a water passageis extended toward the casing body and secured to an outlet/inletopening in the casing body directly or through a cylindrical member,enables corrosion resistance to be imparted to the flow path by havingonly the casing body or both the casing body and the cylindrical memberformed from a corrosion-resistant material.

The arrangement that a retainer plate, which has an annular ribcomprising a planar portion defining the bottom of a U-shaped crosssection and has in the planner portion a plurality of bolt holesrespectively corresponding to bolt holes provided in the flange body anda square box-shaped portion formed at the outer side of the planarportion and which further has a raised face formed integral with theannular rib at the inner side thereof or at each of the outer and innersides thereof so as to abut against the reverse side of the flange face,is attached to the reverse side of the flange face, enables the retainerplate to function as a reinforcing member for the flange face andfurther enables the edges of the square box-shaped portion to functionas straight reinforcing ribs for preventing deformation of a portionwhich extends between each pair of adjacent bolts and also serves toenhance torsional rigidity.

The arrangement that a reinforcing flange comprising a cylindricalportion having a larger diameter than an outlet/inlet opening in thecasing body, an extended portion formed by outwardly extending the endportion of the cylindrical portion on the side thereof which is closerto the flange and provided with bolt holes corresponding to bolt holesin the flange face and the retainer plate, and a casing-side end portionformed in conformity with the configuration of the casing body isinstalled at the reverse side of the flange body, enables prevention ofdeformation caused by external force applied to the flange body.

Formation of a rib on the cylindrical portion of the reinforcing flangeenables even more effective prevention of any deformation of the flangebody.

Since portions which are contacted by pumped fluid, such as the flangebody, and portions which are not contacted by pumped fluid, such as theretainer plate and the reinforcing flange, can be separated from eachother, it is possible to design these two different kinds of portions insuch a manner that, for the portions which are contacted by pumpedfluid, greater importance is attached to corrosion resistance, whereas,for the portions which are not contacted by pumped fluid, greaterimportance is attached to strength. Thus, design for corrosionresistance and strength is facilitated and it is possible to effectivelyutilize a costly material having excellent corrosion resistance.

INDUSTRIAL APPLICABILITY

Thus, the pipe joint for a pump according to the present inventioncomprises a flange body produced from a steel plate such that the innerperipheral portion that defines a water passage is extended toward thecasing body and secured by welding to an outlet/inlet opening in thecasing body directly or through a cylindrical member, the flange bodyhaving a plurality of bolt holes provided in a flange face thereof, anda retainer plate installed in such a manner as to abut against thereverse side of the flange face, the retainer plate having an annularrib with a square outer shape and a U-shaped cross section whichprojects toward the casing body, the annular rib being provided in thebottom of the U-shaped cross section with a plurality of bolt holes inthe flange face respectively corresponding to the bolt holes, theretainer plate further having a raised face formed integral with theannular rib at the inner side thereof or at each of the inner and outersides thereof such that the raised face abuts against the reverse sideof the flange face. Accordingly, the present invention may be suitablyemployed as a pipe joint for a pump wherein it is required for the flowpath to be corrosion resistant and the flange joint surface needs highlyrigid and a large external force acts on the flange in such a manner asto deform it.

I claim:
 1. A pipe joint for a pump including a pump casing having apipe connecting flange, comprising: a flange body produced from a steelplate such that an inner peripheral portion thereof that defines a waterpassage is extended toward the casing and secured by welding to anoutlet opening in said casing, said flange body having a plurality ofbolt holes provided in a flange face thereof; and a retainer plateinstalled in such a manner as to abut against a reverse side of saidflange face, said retainer plate having an annular rib with a squareouter shape and a U-shaped cross section which projects toward thecasing, said annular rib being provided in the bottom of the U-shapedcross section with a plurality of bolt holes respectively correspondingto said bolt holes in the flange face, said retainer plate furtherhaving a raised face formed integrally with said annular rib at an innerside thereof such that said raised face abuts against the reverse sideof said flange face.
 2. A pipe joint for a pump according to claim 1,wherein said retainer plate has a second raised face formed integrallywith said annular rib at an outer side thereof such that the secondraised face abuts against the reverse side of said flange face.
 3. Apipe joint for a pump according to claim 1, further comprising areinforcing flange including a cylindrical portion having a larger borethan that of the outlet opening in the casing, an extended portionformed by radially outwardly extending an end portion of saidcylindrical portion on a side thereof which is closer to the flange,said extended portion being joined to an outer cylindrical portion ofthe flange body, said extended portion being provided with bolt holesrespectively corresponding to said bolt holes in the flange face, and acasing-side end portion of said cylindrical portion which is formed inconformity to the configuration of the casing and welded thereto, saidreinforcing flange being installed in such a manner as to abut againstthe bottom of the annular rib of said retainer plate.
 4. A pipe jointfor a pump according to claim 3, wherein an outwardly projecting rib isprovided on a part of the cylindrical portion of said reinforcingflange.
 5. A pipe joint for a pump according to claim 2, furthercomprising a reinforcing flange including a cylindrical portion having alarger bore than that of the outlet opening in the casing, and anextended portion formed by radially outwardly extending the end portionof said cylindrical portion on a side thereof which is closer to theflange, said extended portion being joined to an outer cylindricalportion of the flange body, said extended portion being provided withbolt holes, and a casing-side end portion of said cylindrical portionwhich is formed in conformity of the casing body and welded thereto,said reinforcing flange being installed in such a manner as to abutagainst the bottom of the annular rib of said retainer plate.
 6. A pipejoint for a pump according to claim 5, wherein an outwardly projectingrib is provided on a part of the cylindrical portion of said reinforcingflange.
 7. A pipe joint for a pump including a pump casing having a pipeconnecting flange, -comprising: a flange body produced from a steelplate such that an inner peripheral portion thereof that defines a waterpassage is extended toward the casing and secured by welding to an inletopening in said casing, said flange body having a plurality of boltholes provided in a flange face thereof; and a retainer plate installedin such a manner as to abut against a reverse side of said flange face,said retainer plate having an annular rib with a square outer shape anda U-shaped cross section which projects toward the casing, said annularrib being provided in the bottom of the U-shaped cross section with aplurality of bolt holes respectively corresponding to said bolt holes inthe flange face, said retainer plate further having a raised face formedintegrally with said annular rib at an inner side thereof such that saidraised face abuts against the reverse side of said flange face.
 8. Apipe joint for a pump according to claim 7, wherein said retainer platehas a second raised face formed integrally with said annular rib at anouter side thereof such that the second raised face abuts against thereverse side of said flange face.
 9. A pipe joint for a pump accordingto claim 7, further comprising a reinforcing flange including acylindrical portion having a larger bore than that of the inlet openingin the casing, an extended portion formed by radially outwardlyextending an end portion of said cylindrical portion on a side thereofwhich is closer to the flange, said extended portion being joined to anouter cylindrical portion of the flange body, said extended portionbeing provided with bolt holes respectively corresponding to said boltholes in the flange face, and a casing-side end portion of saidcylindrical portion which is formed in conformity to the configurationof the casing and welded thereto, said reinforcing flange beinginstalled in such a manner as to abut against the bottom of the annularrib of said retainer plate.
 10. A pipe joint for a pump according toclaim 9, wherein an outwardly projecting rib is provided on a part ofthe cylindrical portion of said reinforcing flange.
 11. A pipe joint fora pump according to claim 8, further comprising a reinforcing flangeincluding a cylindrical portion having a larger bore than that of theinlet opening in the casing, and an extended portion formed by radiallyoutwardly extending the end portion of said cylindrical portion on aside thereof which is closer to the flange, said extended portion beingjoined to an outer cylindrical portion of the flange body, said extendedportion being provided with bolt holes, and a casing-side end portion ofsaid cylindrical portion which is formed in conformity of the casingbody and welded thereto, said reinforcing flange being installed in sucha manner as to abut against the bottom of the annular rib of saidretainer plate.
 12. A pipe joint for a pump according to claim 11,wherein an outwardly projecting rib is provided on a part of thecylindrical portion of said reinforcing flange.
 13. A pipe joint for apump according to claim 1, wherein said flange body is attached to saidcasing directly.
 14. A pipe joint for a pump as recited in claim 1,wherein said flange body is attached to said casing through acylindrical member.
 15. A pipe joint for a pump according to claim 7,wherein said flange body is attached to said casing directly.
 16. A pipejoint for a pump as recited in claim 7, wherein said flange body isattached to said casing through a cylindrical member.
 17. A pipe jointfor a pump including a pump casing having a pipe connecting flange,comprising: a flange body produced from a steel plate such that an innerperipheral portion thereof that defines a water passage is extendedtoward the casing and secured by welding to an outlet opening in saidcasing, said flange body having a plurality of bolt holes provided in aflange face thereof; a retainer plate installed in such a manner as toabut against a reverse side of said flange face, said retainer platehaving an annular rib with a plurality of bolt holes respectivelycorresponding to said bolt holes in the flange face, said retainer platefurther having a raised face formed integrally with said annular rib atan inner side thereof such that said raised face abuts against thereverse said of said flange face; and a reinforcing flange connectingsaid annular rib of said retainer plate with said casing.